• Korean Journal of Materials Research
• /
• v.8 no.3
• /
• pp.252-255
• /
• 1998

In this paper, we investigate the magneto-impedance(M1) effect of the FeCoSiB amorphous magnktic films. The amorphous magnetic film having near zero magnetostriction is fabricated by using the sputtering method, and then annealed in magnetic field. When the external magnetic field is directly applied to the fabricated film, the voltage amplitude between both side of the magnetic film varies about 76.2% at 120[MHzl and the impedance varies about 2.1%/0e. Thus, we find that the fabricated magnetic film has the characteristics of good sensor element.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.11a
• /
• pp.138-138
• /
• 1998

• Journal of the Korean Magnetics Society
• /
• v.13 no.5
• /
• pp.193-197
• /
• 2003

To materialize the magnetoelastic devices, such as a highly functional sensor and a signal processing device, using the Fe base amorphous film which has both excellent soft magnetic and magnetostrictive properties, in this study, a new method to control the magnetic anisotropy of a highly magnetostrictive film using bias stress has been proposed and tested. The film pattern, which was stressed by its substrate bending, was subjected to annealing for relieving its stress. Successively, the compressive stress occurred by flattening the substrate was formed in the pattern. With the introduction of the residual compressive stress, the magnetization of the film pattern was aligned in the transverse direction through magnetoelasic coupling. The magnetic domain structure and magnetization curve of the film pattern of which magnetic anisotropy was controlled by the proposed method were presented to verify the availability of the method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.12S
• /
• pp.1305-1309
• /
• 2003

To utilize FeCoSiB amorphous films for magnetoelastic sensors, the temperature dependency of magnetization (M-T curve) and the magnetization properties of the amorphous films were investigated in this study. As the amount of cobalt In the films increased, the Curie temperature decreased but the crystallization temperature increased. In addition to this, the crystallization temperature was lower than the Curie temperature in the film containing 20 at% cobalt. The optimized annealing condition was set up by analyzing the H-T curve. And then, the amorphous film that has excellent magnetic properties and uni-axal anisotropy could be prepared for construction of the magnetoelastic sensor devices. The coercive force of the film was below 0.5 Oe and the anisotripic field was about 5 Oe.

• Journal of Sensor Science and Technology
• /
• v.9 no.1
• /
• pp.22-27
• /
• 2000

Amorphous FeCoSiB films with high saturation magnetostriction and excellent soft magnetic properties have been studied to evaluate their strain sensitivity. Films were subjected to a strain by bending of their substrates, which caused a change in the magnetic anisotropy of films via magnetoelastic coupling. Films were exhibited a figure of merit $F=({\Delta}{\mu}/{\mu})/{\varepsilon}$ (change in film permeability $\mu$ per unit strain $\varepsilon$) of $1.2{\times}10^5$, which is comparable with that of amorphous ribbons. To make a study of application of magnetostrictive films as strain sensor elements, we have prepared a micro-patterned film by means of the photolithography and ion milling processes. Impedance change in the patterned films, when strain was applied, was measured over the frequency range from 1 MHz to 1 GHz. Reflecting a large value of figure of merit F, a variation of 46% impedance of films was shown at 100 MHz frequency when a strain of $300{\times}10^{-6}$ was applied.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.5
• /
• pp.413-417
• /
• 1998

In this paper, we investigate frequency dependance of inductance of FeCoB amorphous magnetic films. $(Fe_{1-x}Co_x)_{79}Si_2B_{19}$ was used as the basic composition of amorphous magnetic film having near zero magnetostriction. The amorphous magnetic films were fabricated with x=0.94 and x=0.95 by using sputtering method at high frequency. The films were anneald under non-magnetic field and near crystallization temperatures(30min at $280^{\circ}C$, 30min and 1hr at $400^{\circ}C$, respectively). As the results of the experiments with the fabricated films, the lowest coercive force was 0.084[Oe] at 400[W] of the input power and the crystallization temperature was $360^{\circ}C$ . In the case 30min at 40$0^{\circ}C$ the inductance value in the low frequency with x=0.95 was higher by 488% than that with x=0.94. The quality factor Q was below 0.7 for all samples. We obtained the highest quality value at 400[KHz] with 30min at $280^{\circ}C$ and x=0.94. The value was about 0.62. Also, the quality factor value was about 0.35 at 1[MHz] with 30min at $280^{\circ}C$ and x=0.95.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.05a
• /
• pp.27-30
• /
• 1996

In this paper, we prove through the experiments the possibility that Co-amorphous magnetic films can be used as high sensibility materials. We fabricate amorphous film of Fe$\sub$4.7/Co$\sub$74.3/Si$_2$B$\sub$19/ by using sputtering method at high frequency. Then, we not only measure the magnetic Properties of the annealed samples, but also observe the magnetic domain by using an Kerr effect optical-microscope. As the result, we find that the samples have high sensibility